1. Field of the Invention
This invention relates generally to solar collectors and, more particularly, to an apparatus and method for forming a solar collector by an extrusion process utilizing ceramic or similar materials. This invention also relates to manifolds for fluidly interconnecting a series of extruded solar collectors. Additionally, this invention still further relates to building roof construction composed of a plurality of extruded solar collectors positioned side by side and interconnected by a unique manifold system. Finally, this invention further relates to manifolds with improved nipples to effect a more secure coupling of manifolds to solar collectors and with improved manifold ends to effect a more secure coupling between manifolds.
2. Description of the Background Art
Presently, the substantial increase in the cost of fuel has encouraged investigation into alternative forms of energy to meet the needs of coming generations. Significant emphasis has been placed on the investigation of nuclear power, wind power, wave power and solar power. Among the most promising of these alternatives is the collection of solar energy. Solar energy has the advantage of being environmentally safe and producing no waste products. In addition, the source of power is essentially limited only by the number of collectors constructed. Solar collectors are also capable of operation at almost any location without concern for environmental impact on the location.
Experience has shown that the most economical solar collectors comprise liquid heating solar collectors which are capable of being mounted of the roof of commercial and residential buildings. These liquid heating solar collectors typically comprise aluminum, copper or other metallic solar collectors which are relatively costly to manufacture. While less expensive plastic extruded solar collectors have been developed, the relatively high cost of both of these types of collectors has discouraged the widespread use of the units on building installations. In addition, such state-of-the-art solar collectors typically cannot withstand the exposure of sunlight and other environmental factors and, therefore, degrade with time.
In my prior application, Ser. No. 921,053, now U.S. Pat. No. 4,170,983, the disclosure of which is hereby incorporated by reference herein, I invented a unique method and apparatus for manufacturing solar collectors from a liquid ceramic material. The solar collectors were formed by positioning a first and a second mold element of a liquid absorbing material relative to one another to form a mold cavity. The mold cavity defined the outer configuration of the solar collector. The mold cavity was then filled with a curable material, such as liquid ceramic material or any other material which cures upon the loss of liquid. The mold cavity was drained when the curable material was cured adjacent to the first and second mold elements, thereby removing the internal uncured material to define the internal configuration of the solar collector. The solar collector was then fired to provide a solar collector of a ceramic material having input and output manifolds with a plurality of fluid connection paths extending therebetween.
The use of ceramic as a component material for a solar collector can be readily appreciated by those skilled in the art. History has established that ceramic material is durable for use as a roof tile and like. Accordingly, my prior invention provided a low-cost system which is durable, thereby resulting in a feasible solar collector for commercial and domestic installations. The raw material costs and manufacturing costs are extremely low in comparison to conventional aluminum, copper and other metallic solar collectors now known in the art. Further, in comparison to plastic solar collectors, ceramic solar collectors are impervious to the adverse effects of the environment, including ultraviolet radiation from the sun.
Possibly the only disadvantage to my prior invention, now U.S. Pat. No. 4,170,983, is the requirement of a large number of mold elements for mass production. Accordingly, my new invention disclosed below utilizes the same advantages of ceramic materials, with further production capability using an extrusion process to form a main body member of the solar collector of the desirable ceramic material or the like.
It is noted that U.S. Pat. No. 4,114,597 teaches the use of an extrusion process for a thermal setting material. Unfortunately, such material does not have the thermal conductive properties of ceramic material nor the reliability, ruggedness and historical tests of time of ceramic materials. In addition, the use of ceramic material in an extrusion process provides a unique method whereby a substantially integral or one-piece collector may be formed by an extrusion process and then interconnected with similarly formed ceramic collectors having a large surface area.
Indeed, state-of-the-art solar collectors are typically required to be mounted upon a roof or other solid support base in order to support the individual collector elements thereon. Consequently, there exists a need for a solar collector of such strength and durability that the solar collector itself may be supported by roof joists or the like to constitute the roof of a structure.
Therefore, it is an object of this invention to provide an apparatus and method which overcomes the aforementioned inadequacies of the prior art apparatuses and methods and provides an improvement which is a significant contribution to the advancement of the solar collector art.
Another object of this invention is to provide an apparatus and method for extruding a ceramic solar collector in significant lengths having great durability and rigidity and which may be assembled together to constitute the roof of a structure.
Another object of this invention is to provide unique manifolds to interconnect the inputs and outputs of a row of extruded ceramic solar collectors which can be accomplished in the field by relatively inexperienced artisans.
Another object of this invention is to provide connectors for interconnecting, end to end, a series of extruded ceramic solar collectors to produce a solar collector having a length several times longer than the extruded length and which may then be connected to adjacent serially connected extruded ceramic solar collectors by use of the manifolds.
Another object of this invention is to provide a solar collector comprising a transparent material, such as glass, mounted upon a support material, such as closed-cell foam glass, affixed to the surface of the interconnected, extruded ceramic solar collectors to create a "greenhouse" effect thereby increasing the efficiency of the solar collector.
Another object of this invention is to provide a method and an apparatus for manufacturing an economical extruded ceramic solar collector using readily available ceramic materials such that the resultant solar collector may be manufactured throughout the world.
Another object of this invention is to provide manifolds with improved coupling arrangements between manifold nipples and a solar panels having nipple receiving orifices, wherein each nipple is formed with a plurality of primary circumferential projections adjacent to the free forward end and a supplemental circumferential projection adjacent to the manifold, the primary projections having radial surfaces as well as surfaces inclined in a first direction while the supplemental projection has a radial surface as well as a surface inclined in the opposite direction and the coupling arrangement further includes a circumferential recess in each interior orifice of the solar collector, shaped and locate for receiving its associated additional projection.
Lastly, it is an object of the invention to provide manifolds with improved connectors at their ends to ensure secure coupling therebetween.
The foregoing has outlined some of the more pertinent objects of the invention. These objects should be construed to be merely illustrative of some of the more prominent features and applications of the intended invention. Many other beneficial results can be attained by applying the disclosed invention in a different manner or modifying the invention within the scope of the disclosure contained herein and in the above identified patents, the disclosure of which is hereby incorporated by reference herein. Accordingly, other objects and a fuller understanding of the invention may be had by referring to the summary of the invention and the detailed description of the preferred embodiment in addition to the scope of the invention defined by the claims taken in conjunction with the accompanying drawings.